Method for handling strands



1939- J. N. SELVIG METHOD FOR HANDLING STBANDS Filed NOV. 15, 1936 FIG. I

FIG. 5

INVENTOk J. N. SELV/G ATTORNEY Patented Nov. 21, 1939 2,180,554 METHOD son HANDLING STRANDS.

John N. Selvig, Westfield,

ern Electric Company,

N. .11., assignor to West- Incorporated, New York,

Claims.

This invention relates to a method for handling strands and more particularly to a method for forming a sheath of pulpous material on wire.

In the manufacture of certain types of insulated strands for use as electrical conductors, a ribbon or tape of paper pulp is formed in a paper making machine and a metal conductor strand is applied thereto, The pulp tape is then formed 1 into a substantially seamless sheath about the strand and dried to produce a conductor strand having an insulating sheath of highly porous, substantially seamless, interfelted cellulosic fibres. A ridge of the Sheathing material, however, is apt to be formed running longitudinally along the conductor where the fibres of each of the original edges of the pulp tape were interfelted with the body of the tape, and while the presence of these ridges is ordinarily Lmobjectionable and harmless, there may be instances, as in the manufacture from the insulated strands of certain types of compound conductor for uses requiring close limits of capacitative balance or unbalance along associated strands, where it is desirable to control the radial orientation of the ridges along the strand.

An object of the present invention is to provide a method for making pulp insulated strands in which the radialorientation of the pulp sheath ridges with respect to the strand varies in a predetermined, regularly cyclic fashion along the sheathed strand.

One embodiment of the invention contemplates a method for forming a substantially flat tape of p-ulpous material and applying a conductor strand thereto in such fashion that one of the two waves to and fro laterally with respect to the other, so that when the tape is subsequently closed about the strand and its edges interfelted 0 to form a seamless sheath, the ridges created by the interfelted edges will lie in regular, cyclically recurrent, alternately right and left hand spiral formation along the strand.

Other objects and features of the invention 5 will clearly appear from the following detailed description of one embodiment thereof in an apparatus for carrying on the method of the invention for making pulp insulated conductor strands, taken in connection with the accompanying drawing in which the same reference numerals are applied to identical parts in the several figures and in which Fig. 1 is a schematic view in side elevation of the apparatus;

; Fig. 2 is an enlarged, broken view in end elevation, on the line 22 of Fig. l, of a portion of the cylinder mold showing decklesthereon for forming one type of tape;

Fig. 3 is a similar view showing another form ofdeckles; .5.

Fig. 4 is a view of an alternative form of guide sheave; and I Fig. 5 is a view of a portion of the product.

In the apparatus herein disclosed for carrying on the method of the invention, there is a horizontally disposed semi-cylindrical tank Zfiwithin which is coaxially mounted a rotatable drum iii of wire mesh. The tank is filled outside the drum'to the level indicated at 122 with a liquid dispersion of paper pulp in water such as is customary in the paper making art. This liquid tends to pass through the wire mesh of the drum into the interior thereof but is maintained within the drum at the lower level indicated at 23 by a pump of suitable construction not shown, whose H intake is indicated at 24) and which pumps the liquid out, e. g. through the hollow shaft 25 of the drum and back into the tank outside the drum.

In passing through the wire mesh, the pulp fibres are deposited thereon while the water passes through. As shown in Fig. 2, in a preferred form of the invention, the wire mesh is covered except as to a desired area, by circumferential strips26 and 2! of impervious material known as deckles. These, in the present in- 30 stance, are formed, as shown, to leave the mesh bare in a regularly sinuously waved zone 28 around the drum. Hence the tape of pulp formed between these deckles will be similarly, laterally and predeterminedly wavy.

A suitable conductor strand 3E3 drawn from a 35 supply reel 35 passes over a guide sheave 32, which in the present instance isof ordinary construction, and thence passes down into the tank 28 and comes tangentially upon the wire mesh 0 surface of, the drum 24 between the deckles 25 and 2'? at a point, indicated at 33, below the line 22. Sincethe pulp liquid is at a higherlevel outside than inside the drum 2!, the liquid tends to how inwardlyv through the mesh and deposits its burden of pulp upon the mesh between the 'deckles. The strand 31 reaches the drum after this action'has started and is therefore laid upon a partly formed ribbon or tape of deposited pulp. The depositing action continues and the remainder of the tape thickness is laid on over the strand until the tape 29 with the strand embedded therein emerge at the right hand side of the drum at the point indicated at 34 from the bath of liquid. 5

Above the drum an endless belt or blanket 35 of felt material is supported on an idler roll 36 and a driven roll 31 and is forcibly pressed against the top of the drum 2! by a third roll 38. The newly formed pulp tape containing the strand is naturally more or less intermeshed with the wire mesh upon which it is formed. By pressing the felt belt 35 heavily against the tape however, the tape aided by the strand follows the belt 35 and not the drum 2| where these part company, and the tape and wire pass along together over the belt and the rolls 36 and 31 to a former generally indicated at 33, thence through a drying oven 40, and on to a take-up reel 4|. The nature of the construction and mode of operation of the former 39 and of the oven 43 are no part of the present invention and hence are not disclosed. However, reference may be had to U. S. Patent 1,615,418 issued January 25, 1924 upon an application by H. G. Walker et al., for a description of a former and an oven suitable for use in the present apparatus.

The general process for forming paper pulp tapes in the manner above described is here not disclosed in detail as it is no part of the present invention, but reference may be had to U. S. Patent 1,815,381 issued January 25, 1927, upon an application by W. F. Hosford, for a complete description of a suitable process, materials and apparatus.

In the above described method and apparatus, it is evident that there will be formed upon the drum 25 a combination comprising a straight strand 3B embedded roughly centrally in a tape of pulpous material of which the lateral edges wave laterally to and fro, approaching and receding from the strand in cyclical repetition, although always equidistant from each other. Hence when the edges of the tape are folded over in the former 39 a product is produced, as in Fig. 5, in which ridges created by interfelting the edges of the tape with its body will lie in sinuous spiral waves along the strand, alternately left and right hand in lay, ordinarily swinging circumferentially to and fro about the strand over more than half a circumference. Hence, if a straight line in the sheath parallel to the axis of the strand be considered, such a line, over any considerable length, will intersect the ridges as many times as any other similar line. Thus irregularities of form due to the ridges will average along the strand to be distributed with regularity both circumferentially and longitudinally.

In a modified form of the embodiment, the ordinary sheave 32 of Fig. 1 may be replaced by a sheave i32, as shown in Fig. 4, which is positioned at an angle to its axis of rotation, and the wavy edged deckles 23 and 2'! of Fig. 2 may be replaced by straight edged parallel deckles I26 and 121, as shown in Fig, 3. The tape I29 thus formed will have straight, parallel lateral edges and the strand 30 will be laid on the drum 2! by the sheave I32 in a sinuous line as shown in Fig. 3. If the tensions applied in the operation are properly adjusted the sinuosities of the strand will not be pulled straight until the tape and strand together are leaving the blanket belt 35 to enter the former 39.

At this point however, the strand is pulled straight, the tape therefor assumes a correspondingly wavy form and the two together enter the former 39 in the same mutual relation as in the preceding case, and the same ultimate result is produced.

The word strand, as used herein and particularly in the appended claims, is intended to include any wire or filament, whether single, as ordinary wire, or compound, such as the braided compound wire known in the radio art as litzendraht, for example; in short any kind of thread, string, cord, line, wire, filament, or the like of metal or of other material, capable of being treated in the manner described.

The embodiments of the invention herein disclosed are merely illustrative and may be modified and departed from in many ways without departing from the scope and spirit of the invention as pointed out in and limited solely by the appended claims.

What is claimed is:

1. A method of making a sheathed strand, which comprises the steps of forming a tape of wet pulpous material while applying a strand longitudinally thereto to be embedded therein and while effecting a sinuous lateral displacement of one with respect to the other, and forming the tape into a sheath about the strand with the seam of the sheath twisting to and fro about the strand.

2. A method of making a sheathed strand, which comprises the steps of forming a tape of wet pulpous material while applying a strand longitudinally thereto to be embedded therein and while effecting a sinuous lateral displacement of the tape with respect to the strand, and forming the tape into a sheath about the strand with the seam of the sheath twisting to and fro about the strand.

3. A method of making a sheathed strand, which comprises the steps of forming a tape of wet pulpous material while applying a strand longitudinally thereto to be embedded therein and while effecting a sinuous lateral displacement of the strand with respect to the tape, and forming the tape into a sheath about the strand with the seam of the sheath twisting to and fro about the strand.

4. A method of making a sheathed strand, which comprises the steps of forming a tape of wet pulpous material with sinuous lateral edges while applying a straight strand longitudinally thereto to be embedded therein, and forming the tape into a sheath about the strand with the seam of the sheath twisting to and fro about the strand.

5. A method of making a sheathed strand, which comprises the steps of forming a tape of wet pulpous material with straight lateral edges while applying a strand sinuously longitudinally thereto to be embedded therein, and forming the tape into a sheath about the strand with the seam of the sheath twisting to and fro about the strand.

JOHN N. SELVIG. 

